Coal burning stoker



a z a 1 5 J April 10, 1934. H. B. DONLEY COAL BURNING STOKER Filed Dec. 31, 1932 Patented Apr. 10, 1934 UNITED STATES COAL BURNING STOKER Harold B. Donley, Columbus, Ohio, assigno'r to Columbus Metal Products Inc., Columbus, Ohio,

a corporation of Ohio Application December 31, 1932, Serial No. 649,715 6 Claims. (01. 110-45) This invention relates generally to coal stokers for furnaces or other heating apparatus and is more particularly directed to the underfeed type of stokers employing crushed fuel which is deposited in a magazine or hopper and fed upwardly into a retort positioned within the furnace or heating apparatus.

The main object of the invention is to provide means for withdrawing gas or dust from the hopper or fuel magazine should the same find its way back through the stoker, thereby preventing its escape into the furnace room.

Another object of the invention is to form a housing for the exterior working mechanism of the stoker so as to protect said mechanism and.

add to the appearance of the apparatus.

A further object is to arrange the blower for the apparatus within said housing and with the air inlet therefor disposed in communication with the top and interior of the hopper or magazine so that in case any gases should work their way upwardly through the hopper, such gases would be drawn into the inlet of said blower.

A still further'object is to provide a closure for' the hopper with openings formed therein communicating with the atmosphere exterior of the hopper and through which openings air is drawn to the inlet of the blower for creating an air current over the fuel body, within the hopper, so that gas ordust from the fuel will be drawn with the air current, through the blower and into the heating apparatus.

These and other objects will become more apparent from the specification and the accom- 5 panying drawing, wherein:

Fig. 1 is a part vertical sectional view of a heating apparatus showing the improved stoker installed in connection therewith;

Fig. 2 is a transverse sectional view taken on the line 2-2 of Fig. 1.

Referring more particularly to the drawing, the numeral 1 designates a furnace which may be of the usual type and wherein is positioned a retort 2 having its upper portion extending above the fuel bed 3 of the furnace. Connecting the lower end of the retort is a fuel conduit 4 leading to the bottom of a fuel magazine or hopper 5 into which. crushed or powdered coal is deposited. A screw conveyor or other fuel feeding means (not shown) is positioned within the conduit for moving the fuel from the hopper through the conduit and upwardly through the retort. The feeding mechanism includes a motor 6 and a transmission '7 for effecting the proper speed of the fuel feeding means positioned within the conduit 4. During the feeding of the fuel to the retort, air is also being delivered to the retort by means of an air duct 8 through which the air is forced by a fan or blower unit 9, also driven by the motor 6. The

details of the transmission mechanism are clearly set forth in my copending application Serial No. 649,716, filed December 31, 1932.

In apparatus of this type, it may occur that gases or dust may find its way back through the fuel conduit and up through the hopper or fuel magazine, which may be due to the fact that the fuel conduit is at times not entirely filled but leaves open passages through which the gas or dust may flow backward into the magazine. To overcome this condition, an air entrance for the blower is arranged above the hopper to create an air current, over the fuel body, for picking up any gas or dust which may find its way back through the fuel. To this end, a housing 10 is provided which encloses the stoker driving mechanism comprising the motor 6 and the transmission mechanism '7 together with the blower unit 9. The housing 10 forms a part of the fuel hopper 5 and has its side walls 11 and 12 spaced therefrom to provide air passages 13 which are in open communication with the interior of the hopper and housing and consequently the intake of the blower positioned within the latter.

Formed with the upper end of the housing and Y hopper walls are inwardly directed flanges 14 which in turn have their inner edges turned downwardly into overhanging ledges 15 of which the ones formed with the walls 11 and 12 extending over and spaced from the upper edges of the 1 side walls of the hopper. The spacing of the ledges 15 from the upper edges of the hopper provides openings 16 establishing communication, by way of the passages 13, between the interior of the hopper and the blower compartment of the housing 10. The ledges 15 extend downwardly substantially in a plane even with the upper.

edges of the hopper side walls or slightly below the same so as to prevent fuel from entering the passages 13 and clogging-up the openings 16.

Closing the upper end of the housing 10 and overlying the hopper 5 is a hood 17 which has its outwardly and downwardly sloping walls riveted or otherwise secured to the flanges 14. The rearwardly sloping top wall 18 of the hood is provided with an opening which is arranged in registration with the open upper end of the hopper and closed by a lid 19 hinged at its upper end as at 20 to the wall so that the lid may be raised to afford entrance to the hopper. Formed with the lid 19 and the side walls of the hood 17 are louvers 21 through which air enters the hopper and is directed to the housing and in turn to the inlet of the blower 9. These air entrances in the closure for the housing and hopper create, when the blower is in operation, an air current over the fuel body within the hopper which will pick up any dust that may be stirred up by the gravitation of the fuel therein as the same is being fed into the combustion zone of the furnace. This dust laden air is passed through the openings '16 and conveyed through the passages I ,13 to the blower from which the air is forced into the furnace where the dust particles are "consumed. Also, if smoke or gas should find its way back and upwardly through the fuel body,

it would be drawn with the air current and prevented from escaping through the hopper closure and into the furnace room. As the combined areas of the openings comprising the louvers provide a large inlet for the-air, no suction on the fuel body is created, but only effects the formation of a slight air current which, however, is of suflicient strength to carry with it any foreign substance which may be caught therewith. The housing 10 which may be of any suitable design has its wall 22 removably secured so that entrance may be had to the compartment enclosing the mechanism.

From the foregoing, it will be seen that a stoker or fuel feeding apparatus has been provided wherein novel features are incorporated for pre venting smoke or gas from escaping therefrom and finding its way into the room in which the apparatus is installed for operation. These features which include a housing and a perforated closure therefor, encases the driving mechanism for the stoker and also the blower unit therefor, hiding the various parts from view and adding to the appearance of the apparatus as well as providing protection for the mechanism .ar--

ranged therein.

If desired, the wall of the housing 10 located adjacent the inlet for the blower 9 may be provided with an opening 23 which is covered by a pivoted closure plate 24. By the adjustment of the plate so as to vary the size ofthe opening, more or less air may be delivered to the blower directly from the atmosphere exterior of the housing and the suction across the fuel body in the magazine thereby regulated to suit varying conditions.

What is claimed is:

1. In combination with a domestic under-feed stoker including a retort, a fuel conveying conduit communication with the retort, means for supplying air to the retort including a blower and its operating mechanism, of a housing enclosing said blower and mechanism and having a fuel magazine formed therein operatively associated with said fuel conduit; said magazine having an open top constituting a filling opening, and having certain of its walls spaced from the side walls of the housing to provide air passages in open communication with the interior of that portion of the housing containing the bfower and the space above the magazine, a wall enclosing the upper end of said housing and overlying the filling opening of the magazine, a hinged lid in said wall for filling purposes, louvers formed in said wall and lid whereby air may flow through said opening, said space and said passages to the intake of the blower.

2. In combination with a domestic under-feed stoker including a retort, a fuel convening conduit communicating with the retort, means for supplying air to the retort including a blower and its operating mechanism, of a housing enclosing said blower and mechanism and having a fuel magazine formed therein operatively associated with said fuel conduit,:said magazine having an open top constituting a filling opening, and having certain of its walls spaced from the side walls of the housing to provide air passages in open communication with that portion of the housing containing the blower and the space above the magazine, a wall enclosing the upper end of said housing and overlying the filling opening of the magazine, a hinged lid in said wall forfilling purposes, the wall of said housing being provided with an opening in communication with the space above the magazine and the atmosphere exterior of the housing. i

3. In combination with a domestic under-feed stoker including a retort, a fuel conveying conduit communicating with said retort, means for supplying air to the retort including a blower and its operating mechanism, of a housing enclosing said blower and mechanism and having a fuel magazine formed therein operatively associated with said fuel conduit, said magazine having an open top constituting a filling opening, and having at least one of its walls spaced from the walls of the housing to provide an air passage in open communication with the interior of that portion of the housing containing the blower and the space above the magazine and an adjustable air inlet in a wall of said housing for controlling the amount of air delivered thereinto from the atmosphereexterior thereof.

4. In combination with a domestic under-feed stoker including a retort, a fuel conveying conduit communicating with said retort, means for supplying air to the retort including a blower and its operating mechanism, of a housing enclosing said blower and mechanism and having a fuel magazine partly positioned therein, said magazine having an open top constituting a filling opening, and having a wall spaced from the corresponding wall of the housing to provide an air passage in open communication with the interior of that portion of the housing enclosing the blower and the space above the magazine, a closure for the upper end of said housing and overlying the open end of the magazine and means formed with the closure for admitting air therethrough to pass over the fuel in the magazine, through said air passage to the inlet of the blower positioned within the housing.

5. In a domestic under-feed stoker including a retort, a conduit for conveying fuel to said retort and a blower for supplying air to the latter, a housing divided into blower and fuel compartments, said fuel compartment having an open top constituting a filling opening, a cover for said fuel compartment provided with openings communicating with the atmosphere exterior of said housing, and means connecting the blower compartment with the space between the open top of the fuel compartment and its cover for causing the air used by the blower to pass over the fuel contained within the fuel compartment.

6. In a domestic under-feed stoker including a retort, a conduit for conveying fuel to said retort and a blower for supplying air to the latter, a housing divided into blower and fuel compartments, said fuel compartment having an open top constituting a filling opening, a cover for said fuel compartment provided with openings communicating with the atmosphere exterior of said housing, means connecting the blower compartment with the space between the open top of the fuel compartment and. its cover for causing the air used by the blower to pass over the fuel contained within the fuel compartment, and means formed with the side wall of the blower compartment for controlling the amount of air passing through said connecting means.

HAROLD B. DONLEY. 

